Adaptive interaction for enabling pervasive services

Abstract

We describe an architecture that allows mobile users to access a variety of services provided by pervasive computing environments. Novel to our approach is that the system selects and executes services taking into account arbitrary contextual information (e.g. location or preferences). Our architecture is based on an adaptive service interaction scheme; individual service requests are attributed by context constraints, which specify the adaption policy. Context constraints may relate to spatial or temporal concerns. We propose a document-based approach; so called Context-Aware Packets (CAPs) contain context constraints and data for describing an entire service request. Intermediary network nodes route and apply the data to services, which match the embedded constraints. Services are identified by characterizing attributes, rather then explicit network addresses. The execution of selected services may be deferred, and triggered by a specific event. Service requests carry the context of their use, therefore our system works well in environments with intermitted connectivity, less interaction with the issuing requester is required.

Context Awareness in Mobile Computing Environments

“…The idea of introducing an interoperable data format, describing sensor-features among Smart-Its, is based on the Smart Context-Aware Packets (sCAPs). Such protocol may be considered as a document-based approach for collecting sensor-features sharing some similarities with Context-Aware Packets (CAP) [26]. The sCAP is gradually filled with sensed information on its way through the environment.…”

“…Several device prototypes are based on Smart-Its using diverse micro-controller platforms. Smart-Its are used for multi-sensing contextual information for mobile users, similarly to the Smart-CAPs [26]. Moreover, Smart-Its Friends is a context-aware application based on this technology.…”

Group-oriented mobile services: Requirements and solutions

“…The current work on transaction support in mobile environment primarily deals with database access and transaction completion for mobile users experiencing connectivity problems. This includes pre-fetching multiple versions of data (Lam et al 2001), detecting data conflicts between transactions (Lee et al 2000), using synchronization after re-connection to allow the completion of a transaction (Keller et al 1998), reducing interaction under intermitted connectivity (Samulowitz et al 2001), using a runtime infrastructure to reconfigure the application to operate in the disconnected mode of operation (Weinsberg and Ben-Shaul 2002), using pre-write operation to improve data availability during frequent disconnection (Madria and Bhargava 1998), and performing recovery for transactions under mobile disconnection (Pedregal-Martin and Ramamrithan 2002). We define ''group transaction'' to imply a multi-stage transaction with several active mobile users deploying multicast communications (Fig.…”

Supporting dependable group‐oriented mobile transactions: redundancy‐based architecture and performance

“…Although routing and related issues have received considerable attention [2], only very little work exists for transactions in mobile services such as basic requirements [4], mobile teamwork functions [5], and virtual guide function for a tourist group [6]. So far, most of the transactionrelated research primarily deals with database access under connectivity problems such as pre-fetching data [7], detecting data conflicts between transactions [8], deploying transaction recovery [9], using synchronization [10], reducing interaction under intermitted connectivity [11], supporting disconnected mode of operation [12], using middleware [13], using pre-write for data availability during frequent disconnection [14], performing recovery for transactions [15], measuring effect of disconnection on the properties for transactions [16], using recovery protocol [17], deploying transaction manager to retrieve state information [18], and accessing commerce activities using state machines and event management to handle disconnection [19]. The use of basic time-out mechanisms for group-oriented mobile services has been suggested [4].…”